Globe-holder for arc-lamps.



No. 733,596. PATENTED JULY 14, 1903.

R. H. READ.

GLOBE HOLDER FOR ARC LAMPS.

APPLICATION FILED APB.v 3, 1901.

NO MODEL.

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Witnesses Inventor Robert Read. y M M' Atty.

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UNITED STATES Patented July 14, 1903.

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ROBERT H. READ, OF SCHENECTADY, NEYV YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NE YORK.

GLOBE-HOLDER FOR ARC-LAMPS.

SPECIFICATION forming part of Letters Patent N0. 733,596, dated July 14,1903.

Application filed April 3, 1901. Serial No. 54,123. (No model.)

To all whom it may concern:

Be it known that I, ROBERT H. READ, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Globe Holders for Are-Lamps, of which the following is a specification.

The object of this invention is to providea simple and effective devicefor clamping the inner globes of arc-lamps. Considerable dif ficulty isexperienced in practice from the breaking of the globes by reason of thepressure of the clamping devices which secure the bottom of the globe toits support, mounted 011 the yoke of an arc-lamp. The device mustmaintain a firm grip on the globe, so as to make substantially anair-tight joint between its support and the globe-bottom, and yet mustbe sufficiently yielding to prevent breaking of the globe fromcontraction and expansion when the lamp is idle or operating. A rigidclamp has been found ineffective by reason of its unyieldingcharacteristics and inability to permit the necessary expansion andcontraction. I provide a globe-holder by which a number ofelastically-yielding clamp-jaws are supported from the stem of theglobe-holder, which are adapted to slide in grooves formed in ahorizontal rotatory disk mounted on the stem of the holder, the groovesor slots curving toward the axis of the globe, so that when the disk isrotated the clampjaws will be shifted to or from the axis of the globe,so as to grip or release it.

The novel features of the invention will be more specifically describedhereinafter and will be definitely indicated in the appended claims.

In the accompanying drawings, which illustrate the invention, Figure 1is an elevation, partly in section, of a globe-holder embodying theimprovements. Fig. 2 is a detail of the blank from which the clamp-jawsare formed. Fig. 3 is a detail view showing the curved shape of thespring-clamp. Fig. 4 is the rotatory disk which controls the adjustmentof the clamp-jaws.

1 represents a g1obe-holder adapted to be fastened to the yoke of anarc-lamp in the ordinary manner, carrying a stem. on the top of which isa recessed seat 2 for the bottom of an inner globe, (shown at 3.) It isusual to provide a soft lining for the bottom of this seat of asbestos,as indicated in the drawings, 5 5 thereby cushioning the globe andpromoting the tightness of the seal. On the stem of the support I mounta clamp made of sheet metal,

as thin steel or phosphor-bronze, and provided with a plurality ofvertical curved jaws or fingers 4 r. The clamp is made from a blank ofsheet metal of substantially the shape indicated in Fig. 2, theclamp-jaws being curled in some such way as indicated in Fig. 3, and thesupporting-web being curved to hug the stem of the globe-support andprovided with two projecting ears, as indicated in Fig. 1, which areperforated, as indicated at 5 5, to take a set-screw. The globeseat isremovably secured to the stem of the support, being connected thereto bya screw connection, as indicated in Fig. 1, and below the threaded jointis a'shoulder on which is seated, sufficiently loosely to permit itsbeing revolved by the fingers, the regulating-disk 6. The disk may havea milled edge or be otherwise shaped to permit easy turning. It isprovided with a number of slots extending from the periphery inward, asindicated at 7 7 in Fig. 4, into which the spring-jaws may be guided.The inner extremity of the grooves may have an offset, as indicated at8, to lock the jaws in clamping position when set. By turning the diskthrough a small angle the jaws may be shifted into clamping position orreleasing position with relation to the globe, and the latter is firmlyanchored in its seat by an elastic b l l hat I claim as new, and desireto secure by Letters Patent of the United States, is o 1. A globe-holderfor an arc-lamp, comprising a plurality of elastic clamp-jaws extendingabove the plane of the globe-seat, a retatable device having guidesparallel to the plane of the seat and engaging the clamp- 5 jaws alonglines extending outward from the globe-axis, said rotatable device beingarranged to prevent the jaws jarring loose after the globe has beensecured.

2. A globe-holder for an arc-lamp, compris- 10o ing a plurality ofspring-jaws mounted on the globe-support and extending above theglobeseat,'2t rotatable disk having a guide-slot for ing aplurztlity ofelastic clamp-jaws formed each jaw to shift it into and out ofengagefrom a strip of sheet metal having a. web bent ment with the neckof the globe, said disk be- 5 around the globe-support and secured in I5 ing' arranged to prevent the jaws jarring loose place, and aslotteddisk shifting the jaws to after the globe has been secured. and from theaxis of the globe.

13. Aglobe-holder for an are-lamp, eoinpris- In witness whereof I havehereunto set my ing a globe-seait, a plurality of spring-jaws hand this30th day of March, 1901. rigidly attached to the support and extendingROBERT H RFAD above the seat, and a slotted clamp-disk en- J gaging thejaws rotatably mounted on the lVitnesses: support. BENJAMIN B. HULL,

l. Aglobe-holderforan are-hump, compris- FRED RUSS.

